    [Patent document 1] JP-A-2008-262274
A vehicle is mounted with various in-vehicle instruments such as an air-conditioner, an audio, a navigation system, and a communications terminal. A technology is known which enables a driver to operate an in-vehicle instrument while maintaining a body posture for driving manipulation by arranging a manipulating switch in a steering wheel in addition to a switch attached into the instrument itself. For example, Patent document 1 discloses a technology in which a scroll operation in a map displayed in a car navigation apparatus is enabled by using a switch arranged in the steering wheel.
However, there may be existing various manipulating switches (i.e., manipulating devices) for various in-vehicle instruments in the steering wheel. It may be thereby not so easy to recognize the correspondence or association relation between each manipulating switch and each instrument. The user or driver thus needs to move the sight line from a heading direction of the vehicle so as to confirm the intended manipulating switch at hand. Therefore, it is not so easy to find out quickly an intended manipulating switch.